A multifunctional additive of guanidinium chloride (GuCl) in a CH3NH3PbI3 perovskite absorber enabled a high open-circuit voltage of over 1.0 V for printable mesoscopic perovskite solar cells based on a TiO2/ZrO2/carbon architecture.

Mixed‐anion perovskite CH3NH3PbI(3−x)(BF4)x has been developed and optimized to enable a highly efficient hole‐conductor‐free fully printable mesoscopic solar cell. The employment of BF4− in hybrid organic–inorganic halide perovskite significantly improves its optical and electric properties, such as light harvesting ability, carrier concentration, and conductivity, leading to an enhanced power conversion efficiency of 13.24%.

Combining blue micro‐light‐emitting diodes (LEDs) with color conversion layers (CCLs) is a promising approach to develop efficient full‐color displays. However, no such practical display is reported so far potentially because of two major challenges, i.e., rarely available color conversion materials and severe crosstalk effect among adjacent pixels due to the thick sapphire substrates of LED chips. Here, a full‐color micro‐LED display prototype by combining rationally designed blue micro‐LEDs backlight with CsPbBr3 perovskite and CdSe QDs as green and red CCLs, respectively, is presented. The color gamut of the fabricated display can reach as high as 129% of the National Television Standards Committee (NTSC). Notably, the color gamut can still reach 126% NTSC even when only green light is converted through perovskite CCL while the other two colors are achieved from conventional micro‐LEDs. This is the first demonstration on employing perovskite materials as CCL in full‐color micro‐LEDs display.